Carnival barker and Republican Mitt Romney surrogate Donald Trump, R-Absurdity, set the gossip mill churning this week when he declared he would make a “major announcement” about President Barack Obama. “It’s very big — bigger than anybody would know,” he told Fox News Channel.

Would it be a bombshell revelation that Obama sold cocaine in college? The discovery of divorce papers for the president and the first lady?

A betting house set 250/1 odds that Trump would prove that Obama is from another planet, and 500/1 odds that he would announce that he is Obama’s father. The disclosure that Obama is not American was a relatively safe bet, at 2/5 odds.

Story continues below advertisement.

But Trump surprised them all by announcing … absolutely nothing. Instead, he released at high noon on Wednesday what had the look of a ransom video, in which the Donald himself, appearing puffy and unwell, played a character that was part Dr. Evil, part Crazy Eddie.

“I have a deal for the president, a deal that I don’t believe he can refuse,” Trump announced, leaning forward and chopping the air with his hands. “If Barack Obama opens up and gives his college records and applications, and if he gives his passport applications and records, I will give to a charity of his choice … a check, immediately, for $5 million! The check will be given within one hour after he releases all of the records so stated.”

And if you act now, Mr. President, Trump will include an extra added free complimentary bonus gift at no cost to you!

In a singsong voice, Trump teased the president with possible charities that might interest him — “inner-city children in Chicago, American Cancer Society” — and repeated his terms: “All he has to do to get 5 million dollars. … ”

This was trumped up even by the Donald’s self-aggrandizing standards. Denunciations and derision rang out from the political left, right and center. The bookie who took wagers on Trump’s bombshell refunded the money. The real estate mogul had managed to make his real announcement resemble the Onion’s spoof article: “Donald Trump announced that he is a very sad man who has nothing to live for other than drawing attention to himself.”

One beneficiary of Trump’s bust was the publicity-seeking lawyer Gloria Allred, if only because it made her own October Surprise seem somewhat more newsworthy by comparison. She went to court Wednesday with the ex-wife of one of Romney’s former business associates as part of an effort to unseal testimony Romney gave in a 20-year-old divorce case.

Allred’s client is alleging, according to the celebrity gossip website TMZ, that Romney lied when he testified during her divorce from Staples founder Tom Stemberg. Romney, whose Bain Capital backed Staples, allegedly testified that the office supply chain was worth little, so the ex-wife lost out.

Even if true, the Allred surprise seems little more likely to shake up the presidential race than Trump’s histrionics.

The only true October Surprises this year have been executed by candidates themselves — and they aren’t what you’d call happy surprises. The latest belongs to Richard Mourdock, a Republican candidate for Senate in Indiana, who on Tuesday said abortion should be forbidden in all cases because “I think even when life begins in that horrible situation of rape, that it is something that God intended to happen.”

Romney’s campaign distanced itself from Mourdock’s sentiment, and Sen. Kelly Ayotte, R-N.H., canceled an appearance with him. Mourdock, a tea party candidate who already was in jeopardy of losing what had been a safely Republican seat, attempted to clarify his views Wednesday, saying he opposes “any kind of sexual violence.”

Mourdock’s remarks put him in the undesirable category of Todd Akin, the Republican Senate nominee in Missouri who squandered an easy win when he asserted in August that “legitimate rape” rarely causes pregnancy. But Akin had already unveiled an October Surprise of his own: comparing his opponent, Democratic Sen. Claire McCaskill, to a canine.

“It’s a little bit like one of those dogs, you know ‘fetch,’ and she goes to Washington, D.C., and gets all of these taxes and red tape and bureaucracy,” Akin said on Saturday.

Akin’s campaign spokesman, Rick Tyler, later tweeted that McCaskill’s breed would be a bull Shih Tzu — but he spelled it differently.

Surprising, but wrong. We already have had a dog of that variety this campaign season, and his name is Donald Trump.